Method and apparatus for cleaning screen drums in textile machines

ABSTRACT

In one embodiment a drive roll and a finned or fluted cleaning roll are freely mounted within the interior of the screen drum to remove tangles or beards from the interior surface of the screen. In another embodiment, balls are used for the same purpose. The removed fiber material is directed to the inside free space of the screen and eliminated with the carrier airstream.

United States Patent Inventor Daniel Hanselmann Winterthur, Switzerland Appl. No. 782,323 Filed Dec. 9, 1968 Patented Sept. 21, 1971 Assignee Rieter Machine Works, Ltd.

Winterthur, Switzerland Priority Dec. 13, 1967 Switzerland 17505/67 METHOD AND APPARATUS FOR CLEANING SCREEN DRUMS 1N TEXTILE MACHINES 17 Claims, 6 Drawing Figs.

Int. Cl B08b 9/011 Field of Search 134/8, 22,

[56] References Cited UNITED STATES PATENTS 445,534 2/1891 Bidwell 134/8 UX 1,312,291 8/1919 Wicker 19/l56.4 2,229,391 l/1941 Rogers etal. 19/1563 X 2,940,133 6/1960 Heritage [9/1563 X 3,314,840 4/1967 Lloyd et a1 19/156.3 UX

Primary Examiner.1oseph Scovronek Assistant Examiner-D. G. Millman Attorney-Kenyon & Kenyon ABSTRACT: in one embodiment a drive roll and a finned or fluted cleaning roll are freely mounted within the interior of the screen drum to remove tangles or beards from the interior surface of the screen. In another embodiment, balls are used for the same purpose. The removed fiber material is directed to the inside free space of the screen and eliminated with the carrier airstream.

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DHN/E L HANSELMIINN ATTOF: tsv

METHOD AND APPARATUS FOR CLEANING SCREEN DRUMS IN TEXTILE MACHINES This invention relates to a method and apparatus for cleaning screen drums in textile machines. More particularly, this invention relates to a method and apparatus for cleaning the interiors of rotating screen drums in spinning equipment for opening, cleaning, transporting, blending and similar operations of textile fibers.

In spinning mills, fiber material is delivered in flock form from suitable opening equipment and is conveyed, for example, by means of a pneumatic transporting system using a carrier air stream and deposited into a feed or reserve chute of a cleaning machine. Usually, in order to separate these fiber materials from the carrier air stream for depositing, a rotating screen drum is arranged above the chute. The screen drum permits the air stream to pass through the screen perforations while the fiber materials are caught up on the outer surface of the screen drum and thereafter deposited in the chute. In other instances, a rotating screen drum is arranged at the lower end of the feed chute in order to separate the fiber materials out of the carrier air stream. Also, screen drums are used to separate fiber flocks from a carrier air stream for depositing of the separated fiber flocks on a transporting belt. These flocks can also be carried towards the screen drum by means of a transporting belt from which the flocks drop onto the outer surface of the rotating screen drum and are evenly distributed thereover. It is generally known that depositing fiber material on the outer surface of a rotating screen drum quickly results in clogging of the perforations of the screen if there is a drop in pressure from the atmosphere outside the screen drum towards the inside. For example, the individual fibers which penetrate into the screen perforations under the pressure or the suction of an air stream preferentially tend to lap around the bridge or wire between two adjacent perforations or to otherwise stick to the inner drum surface causing the accumulation of further fibers. So-called beards are thus quickly formed, clogging up the perforations of the screen whereby the effective screen surface is progressively reduced and after some time completely loses its effectiveness.

Heretofore, in order to prevent clogging of the perforations of stationary screens, knives have been set close to the screen surface and have been moved relative to the screen surface at a fast rate. These knives have served to separate accumulations and bunches into individual fibers. However, the devices using these knives cannot be mounted to the inside surface of a rotating screen drum since the fibers which would be scraped from the screen would only again collect on the knives in the inside space of the screen drum. In addition, it has been known to lower the velocity of the fiber feeding carrier air stream in order to prevent or at least reduce the penetration of fibers through the perforations. This, however, has involved the risk that the fiber flocks might not be delivered and distributed on the screen drum uniformly enough due to reduced turbulence. Furthermore, this tens to be uneconomical due to the reduction in carrier air and fiber material throughput.

It has also been known to arrange a fan at one end of a screen roll drum in order to eliminate, by suction, the fiber material which has penetrated through the perforations and has accumulated on the inside surface. However, the effectiveness of a fan arranged at one end of a drum while barely sufficient to eliminate free fibers has not been sufficient to eliminate laps or tangles from the inside surface of the screen drum.

Accordingly, it is an object of the invention to eliminate free fiber material from the inside of a rotating screen drum.

It is another object of the invention to avoid formation of beards or tangles on the perforations of a rotating screen drum.

It is another object of the invention to keep the inside of the screen drum clean and free of fibers without additional clean ing operations.

Briefly, the invention provides a method for cleaning a rotating screen drum as used in spinning equipment for opening, cleaning, transporting or blending of textile fibers and similar operations. The method includes the steps of removing any fiber material clinging to the inside surface of the screen drum by a rolling force i.e. by a friction force, for example, as developed by at least one rotating body disposed in sliding engagement with the inside surface of the screen drum, of carrying the removed fiber material to the free inside space of the screen drum, and of eliminating the fiber material from the free inside space of the screen drum by means of an exhaust stream of air. The exhaust stream of air can be generated from a carrier airstream of a pneumatic transporting system which is used to transport the fiber material initially to the outside surface of the rotating screen drum. Thereafter, as the carrier airstream passes through the perforations of the screen drum, the airstream can be exhausted from the inside of the screen drum with the removed fiber entrained therein.

The cleaning apparatus of the invention utilizes at least one rotatable body such as a cleaning roll or ball which is freely mounted within the interior of a rotating screen drum for dislodging accumulated fiber materials projecting through the perforations of the screen. The rotatable body can also be driven by a driving means constituted by a like body such as a drive roll or ball so as to rotate while the screen drum also rotates. The apparatus also includes means for eliminating the dislodged fiber material from the inside of the screen drum.

These and other objects and advantages of the invention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a side view of a screen drum incorporating a cleaning apparatus having a cleaning roll and a drive roll according to the invention;

FIG. 2 illustrates a view taken on line II-Il of FIG. 1;

FIG. 3 illustrates a fragmentary view of a screen drum utilizing a cleaning apparatus of the invention having a modified cleaning roll;

FIG. 4 illustrates an enlarged view of the screen drum, cleaning roll and driving roll of FIG. 1;

FIG. 5 illustrates a view similar to FIG. I having a fluted driving roll; and

FIG. 6 illustrates a fragmentary view of a screen drum utilizing a cleaning apparatus of the invention having a plurality of cleaning balls.

Referring to FIG. 1, fiber material 1 is carried by means of a carrier airstream through a feed duct 2 to a rotating screen drum 3 and deposited on the outer surface of the drum screen 5 in which a plurality of perforations 4 are formed leading to the drum interior. The perforations 4 allow the carrier airstream to penetrate into the interior of the screen drum 3 while the fiber material 1 is separated out on the surface of the screen 5.

Referring to FIGS. 1 and 2, the screen drum 3 which is hollow is rotatably supported at three points by rolls 7 at each end and is provided with a sprocket 9 fixed at one end which is driven by a chain (not shown) of a suitable drive (not shown) at a speed of, for example, 8 to 10 r.p.m. The screen drum 3 also contains a cover 8 which is secured to the end over the sprocket 9 to seal the screen drum at that end.

A cleaning apparatus is provided for cleaning the interior surface of the screen drum 3 and includes a cleaning roll 10 and a drive roll 11 freely placed inside the screen drum 3 parallel to the drum axis and in contact with the interior surface of the screen drum 3.

Referring to FIGS. 1, 2 and 4, the cleaning roll 10 is formed of a hollow cylinder of rubber and has a plurality of projections or fins l3,extending outwardly from the outer surface. Each projection or fin 13 extends at an angle from the outer roll circumference across the entire length of the cleaning roll 10 parallel to the roll axis. Alternatively, as shown in FIG. 3, the projections or fins 15 can be arranged helically across the entire outside surface of the roll 10. The drive roll 11 is formed of a hollow cylinder of rubber and has a smooth outer surface.

Referring to FIG. 4, the cleaning roll 10 is of less weight than the drive roll 11 and is of larger diameter than the drive roll 11 in order to prevent the formation of fly waste accumulations at the ends of the rolls 10, 1 1. In addition, both rolls 10, 11 are situated in the lower part of the screen drum 3 with the axis of each ofiset from the axis of the screen drum 3.

Referring to FIG. 3, in order to prevent axial displacement of the rolls l0, 11 towards the ends of the screen drum 3, members 14 are secured to the ends of the screen drum 3 which are of smaller inside diameter than the screen 5. The members 14 are also slightly tapered towards the inside and have inner rims which are at right angles to the screen 5 so as to form an abutment for the rolls 10, 11.

In operation, referring to FIGS. 1 and 4, the cleaning roll and drive roll 11 are arranged inside the screen drum 3 with the drive roll 11 to the left of the cleaning roll 10 for a rotation of the screen drum 3 in a counterclockwise direction (as indicated by an arrow in FIG. 4). The fins l3 of the cleaning roll 10 are also inclined in the direction of the'screen drum rotation. Upon rotation of the screen drum 3, the drive roll 11 rotates in the same direction due to the friction of its rubber surface on the interior surface of the screen 5 (as indicated by an arrow in FIG. 4). The drive roll 11 due to its frictional contact with the fins 13 of the cleaning roll 10, drives the cleaning roll 10' in the opposite clockwise direction (as indicated in FIG. 4).

A carrier airstream then transports the fiber material 1 via the feed duct 2 to the outer surface of the screen 5 of the rotating screen drum 3. The airstream then flows through the perforations 4 into the interior space of screen drum 3 while the fiber material is deposited on the outer surface of the screen 5. A the same time, the fins 13 of the rotating cleaning roll 10 remove any tangles that form at the perforations 4 or at other places on the interior surface of the screen 5. The fiber material removed after passing the line of frictional contact between the drive roll 11 and cleaning roll 10 is then carried away from the inside by the carrier airstream which passes through the screen 5 and exits via an exhaust duct (not shown) at the uncovered end of the screen drum 3.

It is noted that the fins 13, 15 of the cleaning roll 10, due to their flexibility, are in contact with the interior screen surface along the full length of the roll 10 and thus ensure a cleaning action at all places along the entire contacting length of the roll 10. It is further noted that due to inertia, the rolls 10, 11 are moved towards the right as viewed in FIG. 1 into a slightly elevated position during rotation of the screen drum 3 and fall back into their lowest position at irregular intervals. This results in an additional cleaning action which improved the overall cleaning effect.

Referring to FIG. 5, wherein like reference characters refer to like parts as above, the cleaning roll 10 can alternatively be formed as a hollow roll having integral radially directed flutes 16 in the outer surface which extend over the entire length of the roll 10 parallel to the roll axis. These flutes 16 can also be arranged helically or spirally of the roll 10. The advantage of the flutes 16 over the fins 13 (FIG. 4) is that the position of the rolls 10, 11 can be chosen independently of the direction of rotation of the screen drum 3.

It is noted that the rolls 10, 11 may be made solid and may be provided with cores of different material from the material of the surfaces.

Referring to FIG. 6, instead of using elongated rolls as the rotating bodies in the cleaning apparatus as above described, a plurality of balls l7 can be used. To this end, the balls 17 are provided with a rubber surface 18 and are freely mounted in the interior of a screen drum 3 as shown in FIG. 2. During operation, the balls 17 are rotated due to their frictional con tact on the interior surface of the screen 5 and thereby clean the interior surface of the screen 5. As above, any tangles or beards which form at the perforations 4 are removed by the rolling friction of the balls 17 and are carried by the balls 17 towards the free inside space of the screen drum 3. The fiber material is then eliminated from this space by the airstream flowing through the screen drum 3.

The balls 17, like the rolls l0, 11 may be hollow or may contain a solid core of a material which may differ from the material of the surface.

It is noted that the surfaces of the rotating bodies 10, 11, 16,

5 17 are smooth and bare of any edges or such so that the fiber material which is removed from the interior surface of the screen 5 cannot cling to the rotating bodies.

It is finally noted that the cleaning apparatus can exhaust the removed fiber material from within the screen drum by an airstream, for example, the carrier airstream which carries the fiber material to the screen drum, under pressure or under vacuum by use of a suitable means.

What is claimed is:

1. In combination with a hollow screen drum having a screen therein, a cleaning apparatus comprising at least one rotatable body placed on the interior surface of said screen and in sliding engagement with said interior surface,

driving means for driving said body during rotation of said screen drum to remove fiber material from said interior surface of said screen, and

means for eliminating the removed fiber material from within said screen drum.

2. The combination as set forth in claim 1 wherein said body is a ball.

3. The combination as set forth in claim 1 wherein said body has an outer surface of rubber to permit frictional rolling on said screen upon rotation of said screen drum.

4. The combination as set forth in claim 1 wherein said means for eliminating the removed fiber material generates an airstream flowing through said screen drum.

5. The combination as set forth in claim 1 wherein said body is a cleaning roll and said driving means is a driving roll of greater weight and smaller diameter than said cleaning roll.

6. The combination as set forth in claim 1 wherein said body is an elongated cleaning roll disposed in parallel to the longitudinal axis of said screen drum.

7. The combination as set forth in claim 6 wherein said roll is freely placed on said interior surface of said screen.

8. The combination as set forth in claim 6 wherein said cleaning roll has a fluted surface.

9. The combination as set forth in claim 6 wherein said driving means is a smooth surfaced drive roll disposed parallel to and in frictional contact with said cleaning roll.

10. The combination as set forth in claim 9 wherein said drive roll is placed on said interior surface of said screen for rotation under rolling friction therewith upon rotation of said screen drum.

11. The combination as set forth in claim 6 wherein said roll has a plurality of fins projecting outwardly from the surface thereof for contact with said interior surface of said screen.

12. The combination as set forth in claim 11 wherein said fins are inclined at an angle to said surface of said roll.

13. In combination with a hollow screen drum having a screen therein, a cleaning apparatus comprising at least one rotatable body loosely placed on the interior surface of said screen and in sliding engagement with said interior surface,

a driving means arranged within said screen drum in frictional contact with said body for driving said body during rotation of said screen drum to remove fiber material from said interior surface of said screen, and

means for eliminating the removed fiber material from within said screen drum.

14 A method for cleaning a rotating textile screen drum having a perforated screen for passage of a fiber carrier airstream therethrough from the outside of the drum to the inside comprising the steps of rotating at least one body on the inside surface of the screen to remove fiber material on the inside surface of the screen under a slidable frictional force developed by said rotating body on the inside surface of the screen,

carrying the removed fiber material towards the inside free space of the screen drum, and

directing the airstream from within the screen drum to eliminate the fiber material in said free space from the screen dru m.

15. A method as set forth in claim 14 wherein said fiber material is removed under a frictional drag rolling force on the drive roll is rotated upon rotation of the screen drum to rotate said cleaning roll under frictional contact whereby said cleaning roll removes the fiber material from the interior surface of the screen.

17. A method as set forth in claim 16 wherein said drive roll is rotated under frictional contact with the interior surface of the screen. 

2. The combination as set forth in claim 1 wherein said body is a ball.
 3. The combination as set forth in claim 1 wherein said body has an outer surface of rubber to permit frictional rolling on said screen upon rotation of said screen drum.
 4. The combination as set forth in claim 1 wherein said means for eliminating the removed fiber material generates an airstream flowing through said screen drum.
 5. The combination as set forth in claim 1 wherein said body is a cleaning roll and said driving means is a driving roll of greater weight and smaller diameter than said cleaning roll.
 6. The combination as set forth in claim 1 wherein said body is an elongated cleaning roll disposed in parallel to the longitudinal axis of said screen drum.
 7. The combination as set forth in claim 6 wherein said roll is freely placed on said interior surface of said screen.
 8. The combination as set forth in claim 6 wherein said cleaning roll has a fluted surface.
 9. The combination as set forth in claim 6 wherein said driving meanS is a smooth surfaced drive roll disposed parallel to and in frictional contact with said cleaning roll.
 10. The combination as set forth in claim 9 wherein said drive roll is placed on said interior surface of said screen for rotation under rolling friction therewith upon rotation of said screen drum.
 11. The combination as set forth in claim 6 wherein said roll has a plurality of fins projecting outwardly from the surface thereof for contact with said interior surface of said screen.
 12. The combination as set forth in claim 11 wherein said fins are inclined at an angle to said surface of said roll.
 13. In combination with a hollow screen drum having a screen therein, a cleaning apparatus comprising at least one rotatable body loosely placed on the interior surface of said screen and in sliding engagement with said interior surface, a driving means arranged within said screen drum in frictional contact with said body for driving said body during rotation of said screen drum to remove fiber material from said interior surface of said screen, and means for eliminating the removed fiber material from within said screen drum. 14 A method for cleaning a rotating textile screen drum having a perforated screen for passage of a fiber carrier airstream therethrough from the outside of the drum to the inside comprising the steps of rotating at least one body on the inside surface of the screen to remove fiber material on the inside surface of the screen under a slidable frictional force developed by said rotating body on the inside surface of the screen, carrying the removed fiber material towards the inside free space of the screen drum, and directing the airstream from within the screen drum to eliminate the fiber material in said free space from the screen drum.
 15. A method as set forth in claim 14 wherein said fiber material is removed under a frictional drag rolling force on the inside surface of the screen.
 16. A method as set forth in claim 14 wherein an elongated cleaning roll and a drive roll are disposed on the interior surface of the screen in parallel relation thereto and wherein said drive roll is rotated upon rotation of the screen drum to rotate said cleaning roll under frictional contact whereby said cleaning roll removes the fiber material from the interior surface of the screen.
 17. A method as set forth in claim 16 wherein said drive roll is rotated under frictional contact with the interior surface of the screen. 